Graphene-Supported Cu<i>_n</i> (<i>n</i> = 5, 6) Clusters for CO₂ Reduction Catalysis

Abstract

In recent years, driven by the swift progress in nanotechnology and catalytic science, researchers in the field of physical chemistry have been vigorously exploring novel catalysts designed to enhance the efficiency and selectivity of a broad spectrum of chemical reactions. Against this backdrop, Cu clusters supported on defective graphene (Cun@GR, where n = 5, 6) function as two-dimensional nanocatalysts, demonstrating exceptional catalytic activity in the electrochemical reduction of carbon dioxide (CO2RR). A comprehensive investigation into the catalytic properties of these materials has been undertaken using density functional theory (DFT) calculations. By tailoring the configuration of Cun@GR, specific reduction products such as CH4 and CH3OH can be selectively produced. The product selectivity is quantitatively analyzed through free energy calculations. Remarkably, the Cu5@GR catalyst enables the electrochemical reduction of CO2 to CH4 with a significantly low overpotential of −0.31 eV. Furthermore, the overpotential of the hydrogen evolution reaction (HER) is higher than that of the conversion of CO2 to CH4; hence, the HER is unlikely to interfere and impede the efficiency of CH4 production. This study demonstrates that Cu5@GR offers low overpotential and high catalytic efficiency, providing a theoretical foundation for the design and experimental synthesis of composite nanocatalysts.

Keywords

• electrocatalytic CO₂ reduction reaction
• Cu cluster
• composite catalyst
• first-principles calculations